SUGGESTIONS ON PROPOSING FOR VSOP AO5 OBSERVATIONS
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ARCHIVAL VSOP OBSERVATIONS:
Many sources have already been observed with HALCA (or are
scheduled for the near future). Please look at the archival list of
observations before submitting a proposal. If a source has already
been observed, then strong justification for additional time should be
included in the proposal. Results from previous HALCA observations will
be important in the justification of additional epochs.
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MULTI-EPOCH OBSERVATIONS:
Periodic HALCA observations have severe constraints. Except for
sources near the poles, a source can be observed just two times a
year, separated about six months. Each window is open for only about
three weeks, and the u-v coverage for the two observing windows are
generally very different. Observations of Intra-Day Variable sources,
over a period of a few weeks, can be done very well even with the
present HALCA constaints of difficult maneuvering between sources.
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COORDINATED HALCA and GROUND OBSERVATIONS:
Your proposal may be associated with concurrent ground VLBI
proposals. For example, you may be proposing for ground VLBI
observations at 15 GHz to complement VSOP observations at 5 GHz.
Please indicate such connections clearly in your proposal since
refereeing of these ground and HALCA proposals should be made in a
coordinated way. All such complementary ground-only observations must
be proposed independently to the appropriate ground array, even if it
is intimately related to a HALCA proposal. As an example, if you
propose for a source at 5 GHz using HALCA, but also wish to observe at
15 GHz with a ground array (even during the HALCA observation period),
a separate proposal must be submitted to that ground array.
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`NON-STANDARD' OBSERVATIONS:
Although we anticipate that most proposals will be for continuum
observations of active galaxies, proposals for the OH line (all four
lines), pulsars and the brighter radio stellar objects are invited.
Recent test phase-referencing observations, where the calibrator is
within the HALCA beam (10' at 4.9 GHz; 30' at 1.6 GHz), have been
relatively successful and such proposals will be entertained. Please
send questions to pge@vsop.isas.ac.jp and to efomalon@nrao.edu about
this technique.
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GROUND RESOURCES:
The specification of the ground resources for your experiment is
not necessary, but can be included especially for non-standard
experiments. It is important to specify the need for big ground
telescopes if the correlated flux density with the HALCA observations
is expected to be less than (or measured in previous experiments)
about 0.1 Jy, or if the science goals of the observation require the
additional sensitivity. The available time on these large telescopes
is limited and must be used judiciously.
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LINEAR-POLARIZATION EXPERIMENTS:
Linearly Polarized images have been made with HALCA data and such
proposals can be submitted. However, the tape consumption is twice
that of normal HALCA experiments, so that the observing time for
polarization experiments are limited. Since the VLBA, VLA, ATNF and
Effelsberg are generally allocated for these experiments, they must
have high priority for scheduling. Reduced bandwidth for strong
sources would aid in their scheduling, although most polarization
experiments are signal to noise limited.
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U-V PLOTS AND WHEN TO OBSERVE:
Inclusion of (u-v) coverage plots are not needed for your VSOP
proposal. The observations will be scheduled with the best (u-v)
(generally highest resolution with reasonable two-dimensional
coverage), consistent with the scientific rating and the allotment of
resources. However, recommendations of specific observing times,
(u-v) coverages, and ground resources will be used if possible. The
proposer should give some consideration of the changing (u-v) coverage
and source observation availability when asking for source monitoring
observations, and coordinating with other ground observations or with
x-ray observations. Please use the u-v tables and explanations given
elsewhere.
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WHEN TO SUBMIT A PROPOSAL:
Although the intention is to call for VSOP proposals every four
months, in concert with many ground telescopes, the possible loss of
observing time in the future may preclude a call for proposals on
June 1, 2001. For that reason we suggest that you
submit a proposal for sources even though they may not be observable
with good u-v coverage until early 2002. It is possible that the
constraints associated with the viewing area of sky or the slewing
between sources may change; in which case the mission can be scheduled
much more efficiently if the proposal queue is full.